Angiographic Characteristics of Catheter-Induced Spasm of the Left Main Coronary Artery.

Spasm of the left main coronary artery (LM) is considered to be rare. We investigated the angiographic characteristics of the LM in patients with combined LM and disease involving additional vessels, who underwent coronary artery bypass grafting (CABG) and underwent repeat coronary angiography within 5 years of the CABG, to examine the apparent frequency of spasm of the LM on initial angiography and its possible predictors. A retrospective analysis was performed of patients who underwent coronary angiography in our institute, who were found to have significant LM stenosis and disease involving additional vessels, underwent CABG and repeat coronary angiography within 5 years of the CABG. Data on angiographic characteristics of the LM on the initial angiogram were investigated. Of 84 patients, 17 (20%) were found to have a normal LM on repeat angiography (group A), and 67 (80%) demonstrated significant stenosis (group B). The degree of LM stenosis was milder in the initial angiogram in group A than in group B (64 ± 15% vs 72 ± 14%, p = 0.047). Most patients in group A demonstrated tubular LM stenosis at initial catheterization in comparison to group B (71% vs 18%). Using multivariate analysis, the only predictor for a normal LM at repeat catheterization was found to be tubular stenosis at initial catheterization (odds ratio 123, 95% confidence interval 4.0 to 3696). In conclusion, LM coronary spasm is a common finding, particularly in those with the appearance of tubular stenosis, and it should be excluded even in patients with additional coronary disease in certain instances to prevent unnecessary CABG.